Available evidence indicates that alteration of RNA metabolism occurs during chemically induced liver carcinogenesis. We have found that not only is there an increase in RNA formation, but also there is an anomolous release of nuclear restricted RNA to the cytoplasm, providing a plausible basis for the expression of properties of an undifferentiated cell. We wish to continue an analysis of RNA metabolism by isolation of the several DNA-dependent RNA polymerases from mammalian cells, measurement of their utilization of templates, as chromatin and DNA, and measurement of their changes in carcinogen- treated rats as well as controls subjected to physiological modulation. Additionally we wish to measure the means of RNA transport to cytoplasm by coupled study of altered transport in normal and carcinogen treated animals in vivo. These studies will be carried out by the analysis of RNA release from isolated nuclei as well as in in vivo situation utilizing both gel electrophoresis and DNA-RNA hybridization to identify the RNA species formed and released to the cytoplasm (in vivo) or nuclear bathing fluid (in vitro).